Pump



H. HUEBER Jan. 9, 1934.

PUMP

Filed July 2, 1950 2 Sheets-Sheet 1 Qwvawtoz Jimmy Ember,

Patented Jan. 9, 1934 UNITED STATES I rm Henry Hueber Buflalo, N. Yslim:- to Trice W Corporation, inhale, N. Y.

' mums my 2, use. Serial No. 405,41: '1 Claim. (01. 103-42) Thisinvention relates to a fuel pump andit has for its primary obiecttoprovide a pumpingmechanismwhichwillsupplythefuelto the motor fuelengine in sumcient quantities to 5 meet the demand without excess.

In the transfer of fuel from the supply tank at the-rear of the motorvehicle to the engine carburetor, at a higher level, it has beencustomary to employ the well. known vacuum tank which 19 operated fromthe low pressure influences as obtained from the intake manifold.Lately, this tank has been replaced by a mechanically driven pump whichwas objectionable in that it would supplythefuelinexcesstothatrequiredbythe 1s carburetor, creating a destructive pressure in the pump systemor requiring an idling circuit which served to return the fuel beingpumped back to the supply tank or to the line between the supply tankand the pump.

go The present invention provides an improved pump which will functionin accordance with the demand; to provide a mechanically actuated pumpin which the; piston element will yield in response. to, and becomeineflective under, ab-

normal pressure conditions; and to provide a pump in which the bearingsare automatically fluid packed against the escape of fuel along thepiston rod.

' In the drawings:-

Fig. 1 illustrates the application of the invention to the power plantof a motor vehicle, depicting the pump mounted on the side of the englnecrank case.

Fig. 2 is a sectional view through the pump about on line 22 of Fig. 6and illustrating the mounting of the pump on thecrank case together withthe source of power for-driving the pump. c

Fig. 3 is a sectional view through the valved head the pump as viewed iftaken approximate- 1y on line 3-3 of Fig. 8.

Fig. 4 is a transverse sectional view ofthe pump with the head.removed,or about on line- 4-4 of Fig. 2.

Fig. 5 is a transverse detailed sectional showing taken on line 5-5 ofFig. 2.

Fig. 6 is a plan view of the pump with the cover plate removed for moreclearly depicting the valve arrangements in the head.

Fig. 'l is a sectional view about on line 7--7 of Fig. 8.

Fig. 8 is an enlarged detailed showing of the automatlcal fluid packingfeature.

Referring more in detail to the accompanying drawings, the numeral 1designates the supply tank which is usually located at the rear of themotor and connected by a pipe 2 to the inlet side of the pump 3, theoutlet side being connected by pipe 4 to the carburetor 5 of the engineso 8. Thenumeral'lthecrankcaseof the engine in which is formed anopening through which driving connection between the pump and the enginecam shaft 8 is established, when the engine is utilized as the source ofpower. For this purpose the pump may be provided with an attachingflange 9 adapted to be bolted to the crank case 7.

The pump comprises a cylinder 10, which may be equipped with coolingfins 11, and a piston 12, the latter having its rod 13 slidably mountedin a bearing 14 extending from the cylinder and opening into a fluidpacking chamber 15 which is relatively larger and extends from themount-- ing base or flange 9 inwardly into the crank case. The pistonrod is provided with an enlarged plunger part 16, slidably fltting andoperating in the-chamber 15, and a yoke 17 straddling and engaging anoperating cam 18 at opposed points whereby the action of the cam willreciprocate the piston rod back and forth. To hold the yoke properlyrelated to its cam, the otherwise cylindrical chamber 15 is given apolygonal cross section toward its outer end to receive a like shapedcross head 19 to which the yoke 17 is connected, the walls of the outerend of the chamber being slotted, as at 20, to permit of the adjacentyoke portions moving therein. Disposed at the inner end of the chamber15 is an inlet port 21 (Fig. 8) closed by an outwardly seating valve 22which is backed by a spring 23. Therefore, on the outward movement ofthe plunger 16 toward the cam shaft 8 it will draw in fluid, eithergaseous or the oil as splashed in the crank case, or boih, so that uponthe return stroke of the plunger the fluid will be trapped in the innerend of the chamber 15 and create suiflcient pressure to resist thepassage of any fuel along the piston rod from the piston chamber 10.This provides a fluid packing which is automatically maintained by theplunger 16 with the cooperation of the inlet valve 22. ,The plunger isprovided with a flt which will permit restricted escape of liquid fromthe chamber when under heavy pressure so that the plunger will not becalled upon to act against a non-compressible fluid without some meansof escape.

The piston 12 is in the form of a resilient or spring disc clamped tothe piston rod 13 between a pair of diametral plates 24 which constitutea reinforcement across the center of the disc and leave the portions 12'of the disc on opposite sides of the central reinforcement free to flexback and forth when unduly resisted by the fluid being pumped. Thus, ifthe carburetor has its floatcontrolled needle valve closed by reason ofa suflicient quantity of fuel contained within the float chamber, thepiston will flex toward the pulling or intaking side of the pump andpermit the fluid in advance of the piston to by-pass about theperipheryof the piston. Thus the merely idle back and forth within thecylinder without impelling the fluid therefrom.

6 It will be understood that without the diametral reinforcement 24, thepiston 12 would be strained equally about its periphery by the fluidresistance and would accordingly flex to only a small degree, since suchflexure would cause it to assume a substantially conical shape,requiring displacement of the piston material. The reinforcement,however, insures easy flexure of suflicient amplitude as the lines ofbend are straight, rather than curved as. they might be withoutthe-reinforcement.

The pump is preferably of the double acting type having valved inlet andoutlet passages communicating with the cylinder 10 atits opposite ends,or at opposite sides of the piston. For convenience in assembly andmanufacture these valved ports are'arranged within the pump head 25. Theinlet passage 26 is provided with two ports 2'1 and 28 closed byindependent valves 29 and 30 operating in valve chambers 31 and 32, thechamber 31 communicating through a duct 33 with the adjacent end of thecylinder of the cylinder while while the chamber 32 has communicationthrough ducts 34 and 35 the latter extending lengthwise of the cylinderand opening into the opposite end of the cylinder 10 as indicated at 36.The outlet passage 37 leads from a pair of chambers 38 and 39 in whichare arranged independent valves 40 and 41 controlling ports 42 and 43the latter opening into the adjacent end the former port 42 is connectedby a branch duct 44 to the duct 35 for communicating with the oppositeend of the cylinder. The duct or passage 35 therefore constitutes acommon means for communication between the ducts 34, 36 and 42 althoughseparate ducts may be provided. The several valve chambers 31, 32, 38and 39 are conveniently formed in one side of the head 25 and are closedbya convenient plate 45. I

This arrangement of valves and passages provides a double acting pump inwhich the piston on each stroke is impelling or driving the fluid inadvance thereof out through one outlet port and is intaking a freshsupply of fuel to the rear through an inlet port.

Say, for instance, the piston in Fig. 2 is moving toward the right, thefuel in advance of the piston 12 will be 36, 35, 44, through port 42(unseating valve 40) and passing on and into the common outlet passage37 while at the rear side of the piston a fresh quantity of fuel isbeing drawn in from the inlet passage 26 through port 27 (unseatingvalve 29) into the valve chamber 31 and through 3 passage 33 into theadjacent end of the cylinder 10. The reverse stroke of the piston closesthe valves 29 and 40 and opens the valve 41 to expel the fluid inadvance of the piston through the port 43, chamber 39 and outlet passage3'7, intaking a fresh supply at the rear of the piston through thepassage 26, duct 26', port 28, (unseating valve 30), through chamber 32,duct 34, 35 and 36, into the remote end of .the cylinder. Any tendencyof the fuel to leak along the piston rod in its bearing 14 will, ashereinbefore stated,

be resisted by the fluid packing resulting from the pressureautomatically maintained in the chamber 15 by the plunger part 16 of thepiston rod.

forced out through the ducts m passages Now, if the demand of thecarburetor has been satisfied and therefore no more fuel is desired fromthe pump, the piston 12 will yield away from the then outlet ordeliveryport so that the fuel trapped in advance of the piston will readilyby-pass therearound by reason of the flexing of the opposite portions 12of the disc about the in the cylinder the piston may flex to by-pass thefluid'between the periphery of the piston and the cylinder walls. r

2. A pumphaving a cylinder, a piston within said cylinder, and meansconnected to a central portion of the piston for reciprocating it withinthe cylinder, said piston comprising a resilient disc having a diametralreinforcement, whereby when abnormallyresisted by fluid in the cylinderthe piston may flex along substantially straight lines of flexure toby-pass fluid between its edges and the cylinder walls.

3. A pump having a cylinder, 9. piston within the cylinder, and meansconnected to the piston for reciprocating it, said piston comprising aresilient disc, whereby upon abnormal resistance by fluid in thecylinder the piston may flex to by-pass fluid, said piston having meansassociated therewith for causing it to flex upon substantially straightlines of flexure.

4. A pump having a cylinder with inlet and outlet passages at each endthereof, and means reciprocable in the cylinder for displacing actionupon movement of the means-in each direction, said means including aresilient member constituting a displacing part flexible under abnormalfluid resistance to by-pass fluid.

5. A pump having a cylinder with inlet and outlet passages at each endthereof, and means reciprocable in the cylinder for displacing actionupon movement of the means in each direction, said means including aresilient member constituting a displacing part adapted to flex uponsubstantially straight lines of flexure, whereby when abnormallyresisted by fluid in the cylinder III lines of flexure to by-pass fluid.

6. A pump having a cylinder with inlet and at each end thereof, andmeans reciprocable in the cylinder for pumping action upon movement ofthe means in each directton, said means including a member movable inone direction to by-pass fluid thereabout upon movement of said means inthe opposite direction and movable in said opposite direction to by-passfluid thereabout upon movement of said means in said one direction.

'7. A pump having a cylinder with inlet and outlet passages at each endthereof, and means reciprocable in the cylinder for pumping action uponmovement of the means in each direction, said means having an overalldisplacing area substantially equal to the inner dimension of thecylinder and having a portion movable'to decrease such overalldisplacing area in the presence of abnormal pressure resisting movementof said means in each direction to permit fluid to pass the piston.

HENRY HUEBER.

